Hypertension related diseases are major causes of morbidity and mortality among U.S. blacks. Among blacks and whites, lower levels of education are associated with higher levels of blood pressure, stroke, and CHD mortality. Higher levels of blood pressure in U.S. blacks compared to U.S. whites persist even after controlling for education. Furthermore, it has been demonstrated that individuals living in the southeastern part of the United States continue to have higher stroke and CHD mortality rates than those living in most other areas of the United States. Yet in Africa, for over four decades, hypertension has been regarded as a rare disease among the black Africans. However, recent evidence from hospital and community based populations suggest that hypertension is the most prevalent cardiovascular disease among Africans and constitutes a major public health problem, particularly in West Africa. Furthermore, stroke is an increasing health problem. The proposed study population comprises U.S. black and white students aged 16-25 years from three southern universities and one northern university representing disparate socioeconomic backgrounds. In addition, a group of black Africans of similar age attending a college in Benin City, Nigeria will be studied. The following hypotheses will be tested: (1) U.S. Blacks will have higher or similar blood pressures than African blacks. (2) The prevalence of cardiovascular risk factors will be lower among Africans than U.S. blacks and whites. Furthermore, there will be regional differences associated with cardiovascular risk factors within the United States--higher blood pressure, greater obesity, higher sodium excretion and lower potassium excretion in the south compared to the north. (3) U.S. and African blacks will excrete more sodium and less potassium than U.S. whites. (4) Within the Nigerian population, the determinants of blood pressure will be similar to those in the United States.